New KT150 tubes?

your right wolf,$300 is about the lowest ive seen them plus shipping. most have them for $380 for four plus shipping.
the big question here is to all of us who went out and spent $160 for four kt120's last year are going to want to spend more money now 10 more wpc. thats like twice the price. i think its a rip off. they know everybody will want them because they are new and cool looking. the kt 120's should be around $30-$40 ea and the kt150's around $50-$60,not the $90-$100 premium they are asking for. but we all know in this business tube guys seem to have deep pockets and will pay whatever they cost. i have two jolida amps running in mono. that would be 8 tubes for $750. the 120's are $300. are they really worth double the cost

This is the first I've heard of KT120 quality issues, and I think it's interesting Davide has experienced "erratic" manufacturing when they're made in the same factory as GL tubes (maybe the Gold Lion quality control team should visit other parts of the factory...lazy bastards!). I'd say that's some bad tube luck as New Sensor must have made a batch after lunch on a Wednesday. I don't doubt other people must have had issues at some point with 120s as they're everywhere, but I've made it a quest to find criticism of 120s as they're such a hit. The official score is 752 to 3 against 120s! Also it's interesting to see such interest in 150s when (like me) 120s work so well (except Davide's). Premium 120s with gold pins, etc., have surprisingly never appeared...Psvane should make some of those as I'd try 'em!

The KT-120s sound fine but the internals of 1 were clearly not given a good visual QC... the posts (anode?) for the vertical glowing conductors are shorter above the top mica plate than the other 3 and guaranteed that when circuit protection cuts in, that's the culprit tube.

I do have one dissimilar 120, and since it works fine I ignore that although it did bug me...but I get it. I suppose the good news is the fact that anybody makes tubes at all since it really seems to be a fiddly hands on thing. I watched an entire old film about the Blackburn Mullard factory (somebody here posted the link)...amazing.

Has anyone contacted ARC about using KT150s in their amps?

Also, Naggots, which manufacturer suggests 7000 hours for the KT120?